Playback device, control method, and program

ABSTRACT

In a case where a first access request from a playback controller ( 131 ) is a request for requesting reading or writing in a local storage area ( 111 ), a data access controller ( 135 ) causes a virtual-package-data file system processor ( 122 ) to perform reading or writing of virtual package data in the local storage area ( 111 ) with priority over the reading or writing of application data in an application data area ( 112 ) by a file system processor ( 123 ).

TECHNICAL FIELD

The present invention relates to playback device, a control method, anda program.

BACKGROUND ART

Recent in-vehicle audio-video (AV) equipment have become highlyfunctional and needs to support many multimedia formats. Furthermore,the diversity of applicable input sources is also increasing: there arehard disk drives (HDD), nonvolatile memory devices such as SD carddevices and USB (Universal Serial Bus) devices, optical disk devicessuch as CDs (Compact Disk), DVDs (Digital Versatile Disk), and BDs(Blu-ray Disk), portable AV players such as mobile audio players andmobile AV players, wireless networks such as Wi-Fi, and so on.

In addition, there is virtual package technology that can construct avirtual package by dynamically combining data recorded on a BD-ROM as aread-only optical disk on which moving picture content is recorded anddata recorded on a rewritable recording medium such as a semiconductormemory card, hard disk, or the like, referred to as local storage. Byvirtually constructing a package, virtual package technology can expandthe data recorded on read-only recording media. With virtual packagetechnology, after a BD-ROM on which moving picture content is recordedhas been distributed, the content of the work can be modified. Forexample, by providing, through a network, preview audio-video datastreams previewing content of other works that have not been releasedyet, playback control information for managing those data streams, orthe like, it is possible to constantly release and promote informationabout the latest works to the user, regardless of the time ofdistribution of the BD-ROM. There is the playback device described inpatent reference 1 as the prior art of virtual package technology inrelation to BD-ROMs.

PRIOR ART REFERENCE Patent Reference

-   Patent reference 1: Japanese Patent Publication No. 5032510 (pp.    4-8, FIG. 1)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

By the way, in the BD-ROM standards, there are requirements on localstorage read speed, with levels provided according to the transferspeed. In a case where an application data area for recordingapplication data is also formed in the writable recording medium inwhich the local storage area is formed, then because local storage arearead requests and application data area read requests are processed bytime-division multiplexing, there is a possibility that the localstorage read speed may be reduced.

In addition, because devices that can be mounted in in-vehicleaudio-video equipment are limited by required temperature conditions, ifdevices priced identically with the rewritable recording media used inhousehold audio-video equipment are selected, their specifications areoften lower. Therefore, costs can be kept down by forming an applicationdata area and a local storage area in a single build-in memory mountedin in-vehicle audio-video equipment supporting BD playback function. Insuch cases, however, the local storage read speed of local storage needto be considered. For example, if a read request to the application dataarea occurs during reading of an audio-video data stream from the localstorage area, the read speed of the audio-video data stream read fromthe local storage area is reduced, and this may cause problems such asjerkiness (missing frames) in the video played back or dropouts(skipping) in the audio. Similarly, in relation to write speed, if awrite request for the application data area occurs during writing in thelocal storage area, the processing of one of the write requests will bedelayed, which may cause interference with the viewing and listeningprocess, deterioration in the operability of the in-vehicle audio-videoequipment, or other such problems.

Therefore, an object of the present invention is to prevent thereduction of the transfer speed from a local storage area even when thelocal storage area and an application data area are formed on arecording medium with which sufficient bandwidth cannot be obtained forthe maximum transfer speed.

Means for Solving the Problem

A playback device according to one aspect of the present inventionincludes a virtual-package-data file system processor to treat acombination of first data recorded in a first recording unit and seconddata recorded in a local storage area in a second recording unitincluding the local storage area and an application data area as virtualpackage data and to perform reading and writing of the virtual packagedata; a file system processor to perform reading and writing ofapplication data recorded in the application data area; a playbackcontroller to control playback of the virtual package data; a processingexecution unit to process the application data; and a data accesscontroller to cause the virtual-package-data file system processor toperform reading or writing of the virtual package data according to afirst access request from the playback controller, the first accessrequest requesting reading and writing of the virtual package data, andto cause the file system processor to perform reading or writing of theapplication data according to a second access request from theprocessing execution unit, the second access request requesting readingor writing of the application data; wherein in a case where the firstaccess request from the playback controller is a request for requestingreading or writing in the local storage area, the data access controllercauses the virtual-package-data file system processor to perform thereading or writing of the virtual package data with priority over thereading or writing of the application data by the file system processor.

A playback method according to one aspect of the present inventionincludes a playback control step for controlling playback of virtualpackage data; a virtual-package-data processing step for performingreading or writing of the virtual package data obtained by combiningfirst data recorded in a first recording unit and second data recordedin a local storage area in a second recording unit according to a firstaccess request from the playback control step; a processing executionstep for processing application data recorded in an application dataarea in the second recording unit; a file system processing step forperforming reading or writing of the application data recorded in theapplication data area in the second recording unit according to a secondaccess request from the processing execution step; and a data accesscontrol step for, in a case where the first access request from theplayback control step is a request for requesting reading or writing inthe local storage area, causing the virtual-package-data processing stepto perform the reading or writing of the virtual package data withpriority over the reading or writing of the application data in the filesystem processing step.

A program according to one aspect of the present invention causes acomputer to function as: a virtual-package-data file system processor totreat a combination of first data recorded in a first recording unit andsecond data recorded in a local storage area in a second recording unitincluding the local storage area and an application data area as virtualpackage data and to perform reading and writing of the virtual packagedata; a file system processor to perform reading and writing ofapplication data recorded in the application data area; a playbackcontroller to control playback of the virtual package data; a processingexecution unit to process the application data; and a data accesscontroller to cause the virtual-package-data file system processor toperform reading or writing of the virtual package data according to afirst access request from the playback controller, the first accessrequest requesting reading and writing of the virtual package data, andto cause the file system processor to perform reading or writing of theapplication data according to a second access request from theprocessing execution unit, the second access request requesting readingor writing of the application data; wherein in a case where the firstaccess request from the playback controller is a request for requestingreading or writing in the local storage area, the data access controllercauses the virtual-package-data file system processor to perform thereading or writing of the virtual package data with priority over thereading or writing of the application data by the file system processor.

Effects of Invention

According to an aspect of the present invention, it is possible toprevent the reduction of the transfer speed from a local storage areaeven when the local storage area and an application data area are formedon a recording medium with which sufficient bandwidth cannot be obtainedfor the maximum transfer speed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram schematically showing a configuration of aplayback device according to a first embodiment.

FIGS. 2(A)-2(C) are schematic diagrams showing an example ofconstruction of virtual package data in the first embodiment.

FIG. 3 is a flowchart showing processes performed in the data accesscontroller in the first embodiment.

FIG. 4 is a block diagram schematically showing a configuration of aplayback device according to a second embodiment.

FIG. 5 is a block diagram schematically showing a configuration of theprocessor in the second embodiment.

MODE FOR CARRYING OUT THE INVENTION First Embodiment

A first embodiment will be described below with reference to thedrawings.

FIG. 1 is a block diagram schematically showing a configuration of aplayback device 100 according to the first embodiment. The playbackdevice 100 combines data recorded on a playback-only recording mediumwith data recorded on a rewritable recording medium to construct virtualpackage data, thereby playing back audio-video content.

The playback device 100 includes a BD drive 101, a decoder 102, anoutput controller 103, a network device 104, an interface (hereinafterreferred to as an I/F) 105, a build-in memory 110, and a control unit120.

The BD drive 101 is a drive unit to read data recorded in a BD-ROM 150,which is a type of playback-only recording medium. When a BD-ROM 150 inwhich first data are recorded is inserted, the BD drive 101 functions asa first recording unit in which the first data are recorded.

The decoder 102 decodes compressed audio-video stream data, therebyconverting them to audio data and video data.

The output controller 103 converts the video data decoded by the decoder102 to a video signal receivable by a monitor 160. Here, in a case whereGUI (graphic user interface) video data generated by the control unit120 are input, the output controller 103 superposes the video datadecoded by the decoder 102 and the GUI video data generated by thecontrol unit 120 and converts the superposed video data to a videosignal receivable by the monitor 160. The output controller 103 thenoutputs the converted video signal to the monitor 160.

In addition, the output controller 103 converts the audio data decodedby the decoder 102 to an audio signal receivable by a speaker 161 tooutput it. Here, if audio data such as operation sounds generated by thecontrol unit 120 are present, the output controller 103 combines theaudio data decoded by the decoder 102 with the audio data generated bythe control unit 120 and converts the combined audio data to an audiosignal receivable by the speaker 161. The output controller 103 thenoutputs the converted audio signal to the speaker 161.

Here, a playback unit to perform playback of data is configured by thedecoder 102 and the output controller 103. The playback unit plays back,for example, virtual package data specified by the control unit 120.

The network device 104 is a communication unit for communicating with anetwork such as the Internet.

The I/F 105 is an interface unit for connection of an external device.Here the I/F 105 connects with a memory device 170 as a rewritablerecording medium.

The build-in memory 110 is a shared rewritable recording medium (asecond recording unit) to record both expanded data for expanding datarecorded in the playback-only recording medium, and application data.The build-in memory 110 includes a local storage area 111, which is anarea for recording expanded data, and an application data area 112 forrecording application data managed by the control unit 120.

The local storage area 111 and the application data area 112 in thebuild-in memory 110 may be separated by partitions divided logically. Insuch cases, a maximum capacity for each of the areas can be determinedand a different file system can be used for each of the areas.Furthermore, it may be possible to form each area in the same partitionand to use the same file system for both of them. An EXT type filesystem or a FAT type file system is generally used as the file system.

The control unit 120 controls each unit in the playback device 100.

The control unit 120 includes an optical disk detector 121, avirtual-package-data file system processor (hereinafter referred to as aVPDFS processor) 122, a file system processor (hereinafter referred toas an FS processor) 123, a device detector 124, a memory 125, and aprocessing unit 130.

The optical disk detector 121 detects whether or not an optical disk hasbeen inserted into the BD drive 101 and whether or not the optical diskhas been ejected from the BD drive 101.

The VPDFS processor 122 treats a combination of data (first data)recorded in the BD-ROM 150 and data (second data) recorded in the localstorage area 111 in the build-in memory 110 as virtual package data andperforms reading and writing of the virtual package data.

Here, the VPDFS processor 122 generates virtual-package-data-file-systemdata enabling the combination of data recorded in the BD-ROM 150 anddata recorded in the local storage area 111 in the build-in memory 110to be treated as virtual package data. For example, the VPDFS processor122 analyzes the UDF (Universal Disk Format) file system of the BD-ROM150 and the file system of the build-in memory 110, thereby generatingvirtual-package-data-file-system data that enable the reading andwriting of data files recorded in the BD-ROM 150 and data files in thelocal storage area 111 in the build-in memory 110. Then, the VPDFSprocessor 122 causes the memory 125 to store the generatedvirtual-package-data-file-system data.

In addition, by referring to the virtual-package-data-file-system datastored in the memory 125, the VPDFS processor 122 reads necessary datafiles from the BD-ROM 150 or the local storage area 111 in response torequests from the processing unit 130, and supplies the read data filesto the processing unit 130. Furthermore, by referring to the virtualpackage-data-file-system data stored in the memory 125, the VPDFSprocessor 122 writes necessary data files in the local storage area 111in response to requests from the processing unit 130.

The FS processor 123 performs reading and writing of application data.For example, the FS processor 123 analyzes the file system in thebuild-in memory 110, thereby generating file system data that enable thereading and writing of data files in the application data area 112, andcauses the memory 125 to store the file system data in the memory 125.In addition, in a case where a memory device 170 is connected to the I/F105, the FS processor 123 generates file system data for enabling thereading and writing of data files in the memory device 170 and causesthe memory 125 to stores the file system data.

Further, by referring to the file system data stored in the memory 125,the FS processor 123 obtains necessary data files from the applicationdata area 112 or the memory device 170 in response to instructions fromthe processing unit 130, and supplies the obtained data files to theprocessing unit 130.

The device detector 124 detects whether or not a device has beenconnected to the I/F 105 and whether or not a device has beendisconnected from the I/F 105.

The memory 125 is a storage unit for storing data required forprocessing by the control unit 120. For example, the memory 125 storesthe virtual-package-data-file-system data generated by the VPDFSprocessor 122 and the file system data generated by the FS processor123. Furthermore, the memory 125 temporarily stores data files obtainedfrom the BD-ROM 150, the build-in memory 110, or the device connected tothe I/F 105. In addition, the memory 125 storesshared-memory-availability information generated by the processing unit130. Furthermore, the memory 125 also stores various data generated bythe processing unit 130.

The processing unit 130 executes processing performed in the playbackdevice 100.

The processing unit 130 includes a playback controller 131, alocal-storage-area usage determination unit (hereinafter referred to asan LSA usage determination unit) 132, a program execution unit 133, anapplication-data access processor (hereinafter referred to as an ADaccess processor) 134, and a data access controller 135.

The playback controller 131 controls the playback of the virtual packagedata. For example, the playback controller 131 specifies the virtualpackage data to be played back. Then, the playback controller 131 makesan access request to the data access controller 135, supplies thevirtual package data to the decoder 102, and causes the decoder 102 toperform decoding.

Specifically, when the BD-ROM 150 is played back, the playbackcontroller 131 obtains the playback control data files for playing backany of one or more audio-video stream data files in the virtual packagedata from at least one of the BD-ROM 150 and the local storage area 111in the build-in memory 110. Then, according to the obtained playbackcontrol data files, the playback controller 131 obtains the relevantaudio-video stream data files from at least one of the BD-ROM 150 andthe local storage area 111 in the build-in memory 110, via the dataaccess controller 135 and virtual-package-data file system processor122.

Here, a playback control data file indicates to a file other than anaudio-video stream data file and includes information for constructingtitle and chapter headings, information that ties this information tothe audio-video stream data file, and so on. Playback control data filesare generally recorded in the BD-ROM 150. When the BD-ROM 150 isinserted into the BD drive 101, the playback controller 131 reads theplayback control data files recorded in the BD-ROM 150. At this time, ina case where BD-J programs are present in the BD-ROM 150, the playbackcontroller 131 executes the BD-J programs. If the BD-J programs include,for example, a program for processing the recording of local storagedata in the local storage area 111 by accessing the content producer'sserver, the playback controller 131 checks whether or not updatedinformation is present on the content producer's server via the networkdevice 104. Then, in a case where updated information is present, theplayback controller 131 downloads the playback control data files andaudio-video stream data files as the updated information, and recordsthem in the local storage area 111 via the data access controller 135and the VPDFS processor 122. After that, the playback controller 131obtains the playback control data files from the BD-ROM 150 and localstorage area 111 via the data access controller 135 and the VPDFSprocessor 122, on the basis of the virtual package data, and performsplayback control.

The LSA usage determination unit 132 determines whether or not readingor writing of data is being performed in the local storage area 111 inthe build-in memory 110. For example, the LSA usage determination unit132 monitors data access by the data access controller 135 anddetermines whether or not the playback controller 131 is performingreading or writing of a data file in the local storage area 111 via theVPDFS processor 122. For example, the LSA usage determination unit 132monitors data access by the data access controller 135 and determineswhether or not reading or writing of the data is being performed bysetting the shared-memory availability information stored in the memory125 to ‘valid’ while a data read or write is being performed in thelocal storage area 111 in the build-in memory 110.

The program execution unit 133 executes predetermined processing byrunning application programs. Here, when application data recorded inthe application data area 112 in the build-in memory 110 are requiredduring the execution of the predetermined processing, the programexecution unit 133 makes a request to the AD access processor 134 toobtain the relevant data file.

In response to requests from the program execution unit 133, the ADaccess processor 134 reads and writes application data files in theapplication data area 112 in the build-in memory 110 via the data accesscontroller 135 and the FS processor 123.

Here, the program execution unit 133 and the AD access processor 134constitute a processing execution unit for processing application data.The processing execution unit makes access requests to the data accesscontroller 135 to obtain required application data.

According to a first access request from the playback controller 131,which requests the reading or writing of virtual package data, the dataaccess controller 135 causes the VPDFS processor 122 to perform thereading or writing of the virtual package data. Further, according to asecond access request from the AD access processor 134, which requeststhe reading or writing of application data, the data access controller135 causes the FS processor 123 to perform the reading or writing of theapplication data.

In a case where an access request from the playback controller 131requests reading or writing in the local storage area 111, the dataaccess controller 135 causes the VPDFS processor 122 to perform thereading and writing of the virtual package data with priority over thereading and writing of application data by the FS processor 123.

Here, the memory device 170 records multimedia format as AV files. Thememory device 170 is a rewritable recording medium, such as an SD cardor HDD. The playback controller 131 reads the AV files from the memorydevice 170 via the data access controller 135 and FS processor 123,sends them to the decoder 102, and causes the decoder 120 to perform thedecoding. This enables the playback device 100 to play back the AV filestoo.

Furthermore, in a case where an optical disk that does not use localstorage, such as a DVD or a CD which is not shown in the figures, isinserted in the BD drive 101, the VPDFS processor 122 reads the data inthe optical disk according to a UDF file system, ISO 9660 file system,or the like recorded in the optical disk, without constructingvirtual-package-data-file-system data. This enables the playback device100 to play back content recorded in this type of optical disk as well.

The playback device 100 described above may be implemented as, forexample, a computer including a CPU (Central Processing Unit), a memory,an external recording device such as an HDD (Hard Disk Drive), aread/write device for reading and writing information on portablerecording media such as a CD (Compact Disk) and a DVD (Digital VersatileDisk) media, and a communication device such as an NIC (NetworkInterface Card) for connection to a communication network.

For example, the BD drive 101 may be implemented by a read/write device.The build-in memory 110 may be implemented by an external recordingdevice. The network device 104 may be implemented by a communicationdevice. The control unit 120 may be implemented by loading apredetermined program recorded in the external recording device into thememory and executing it by the CPU.

The decoder 102 and output controller 103 may be implemented bydedicated hardware, or may be implemented by executing a predeterminedprogram by the CPU.

The predetermined program may be downloaded from a recording medium viathe read/write device or from a network via the communication device tothe external recording device and then loaded into the memory andexecuted by the CPU. It may also be loaded directly into the memory fromthe recording medium via the read/write device or from the network viathe communication device and executed by the CPU.

The playback device 100 may also include the monitor 160 and the speaker161.

The specific operation of the playback device 100 according to the firstembodiment will be described below.

<Regarding Processing when Read-Only Recording Medium (BD-ROM 150) isInserted>

When a BD-ROM 150 is inserted into the BD drive 101, the BD drive 101performs media discrimination and recognizes that it is a BD-ROM medium.The optical disk detector 121 detects that the BD-ROM medium isinserted, by means of a signal from the ATAPI-connected BD drive 101.

When the optical disk detector 121 detects the insertion of the BD-ROMmedium, the program execution unit 133 makes a read request of filesystem data to the VPDFS processor 122 via the AD access processor 134and the data access controller 135. According to the read request offile system data, the VPDFS processor 122 obtains the file system datarecorded in the optical disk from the BD drive 101. Then, on the basisof the obtained file system data, the VPDFS processor 122 determines thelogical format of the optical disk. For example, the VPDFS processor 122determines whether it is any of the BDMV format and BDAV format definedin the BD standards, the DVD-Video format, DVD-VR format, and DVD-Audioformat defined in the DVD standards, and a data disk format, differingfrom all of the above, in which moving picture files, audio files, orstill picture files are recorded. The BDMV format, BDAV format,DVD-Video format, DVD-VR format, and DVD-Audio format are standardlogical formats.

Having determined the logical format, the VPDFS processor 122 reports adetermination result of the logical format to the program execution unit133 via the data access controller 135 and the AD access processor 134.On the basis of the reported determination result of the logical format,the program execution unit 133 transmits logical format informationindicating the determined logical format to the playback controller 131in order to cause the playback controller 131 to perform playbackcontrol of the relevant logical format. For example, for the BD-ROM 150,the VPDFS processor 122 determines the BDMV format as the logicalformat. The program execution unit 133 transmits the logical formatinformation indicating the BDMV format to the playback controller 131.

In a case where the logical format information received from the programexecution unit 133 indicates the BDMV format, the playback controller131 makes a mount processing request for the local storage area 111 tothe VPDFS processor 122 through the data access controller 135. Uponreceiving the mount processing request, the VPDFS processor 122 readsthe file system data recorded in the local storage area 111, therebyenabling data files recorded in the local storage area 111 to be writtenand read. Further, from among the local storage data recorded in thelocal storage area 111 for a plurality of BD-ROMs, the VPDFS processor122 finds the local storage data files corresponding to the data filesrecorded in the BD-ROM 150 inserted into the BD drive 101, and combinesthe data files recorded in the BD-ROM 150, which is a read-onlyrecording medium, with the local storage data files recorded in thelocal storage area 111 in the build-in memory 110, which is a rewritablerecording medium, thereby generating virtual-package-data-file-systemdata that can be processed as virtual package data. Then, the VPDFSprocessor 122 causes the memory 125 to store the generatedvirtual-package-data-file-system data.

FIGS. 2(A) to 2(C) are schematic diagrams showing an example of theconstruction of the virtual package data.

FIG. 2(A) shows the data recorded in the BD-ROM 150, and FIG. 2(B) showsthe data recorded in the local storage area 111.

As shown in FIG. 2(C), the VPDFS processor 122 constructs the virtualpackage data by replacing data files shown in FIG. 2(A) with data filesshown in FIG. 2(B), or by adding the data files shown in FIG. 2(B) tothe data files shown in FIG. 2(A).

Specifically, in FIG. 2(C), the ‘MovieObject.bdmv’ data file shown inFIG. 2(A) is replaced with the ‘mo.bdm’ data file shown in FIG. 2(B).Further, in FIG. 2(C), the ‘00001.mp1’ data file shown in FIG. 2(B) isadded to the ‘PLAYLIST’ folder in FIG. 2(A). Furthermore, in FIG. 2(C),the ‘00001.m2ts’ data file shown in FIG. 2(A) is replaced with the‘00001.mts’ data file shown in FIG. 2(B).

The data files other than the data file included in the ‘STREAM’ folderof the ‘BDMV’ folder shown in FIG. 2(A) are playback control data files.Furthermore, the data files other than the ‘rats’ data file shown inFIG. 2(B) are playback control data files.

In a case where a BD-J program (a Java (registered trademark) program)is recorded in the BD-ROM 150, the playback controller 131 launches aJava virtual machine environment (JavaVM) and runs the BD-J program onthe JavaVM. Besides, with the BD-J programs, the playback controller 131decodes the audio-video data streams of content, activates gameprograms, and also connects via the network device 104 to a server orthe like on the Internet, belonging to the content distributor of theBD-ROM 150. Then, the playback controller 131 can obtain local storagedata such as the data shown in FIG. 2(B) and perform partial rewritingor adding of the data recorded in the BD-ROM 150. In addition to partialupdate data of the data recorded in the BD-ROM 150, game progress data,game scores, and other such data can also be stored in the local storagearea 111.

<Regarding Method of Accessing to Read-Only Medium (BD-ROM 150)>

When accessing virtual package, the playback controller 131 makes avirtual package data access request to the data access controller 135.

Having received the virtual package data access request, the data accesscontroller 135 makes an access-device-type check request to ask theVPDFS processor 122 whether it is a request of access to the localstorage area 111 or a request of access to the BD drive 101. Then, inresponse to that, the data access controller 135 obtains anaccess-device-type check reply result from the VPDFS processor 122. Thevirtual package data access request includes full path information orrelative path information for accessing the desired data file. On thebasis of the path information, the VPDFS processor 122 refers to a fileallocation table included in the virtual-package-data-file-system datastored in the memory 125 and identification information for identifyingthe recording device, and determines whether the access request is arequest of access to the local storage area 111 or a request of accessto the BD drive 101. Then, the VPDFS processor 122 generates theaccess-device-type check reply result according to the result of thedetermination.

If the access-device-type check reply result from the VPDFS processor122 indicates a request of access to the BD drive 101, the data accesscontroller 135 sends the VPDFS processor 122 a BD access request. TheVPDFS processor 122 sends the received BD access request to the BD drive101.

The BD drive 101 receives the BD access request from the VPDFS processor122, and reads data from the inserted BD-ROM 150 according to this BDdrive access request. Then, the BD drive 101 sends the read data to theVPDFS processor 122, and the VPDFS processor 122 causes the memory 125to store the received data. Upon completing the reading of the data fromthe BD drive 101, the VPDFS processor 122 sends BD driveaccess-completion notification to the data access controller 135. Whenthe data access controller 135 receives the BD drive access-completionnotification, it sends virtual-package-data access-completionnotification to the playback controller 131.

When the playback controller 131 receives the virtual-package-dataaccess-completion notification, if the issued virtual package dataaccess request is a read request of playback control data, the playbackcontroller 131 itself processes the data. If the issued virtual packagedata access request is a read request of audio-video stream data, theplayback controller 131 transfers the read data from the memory 125 tothe decoder 102 and causes the decoder 102 to decode the audio-videostream data by making a decode start request to the decoder 102.

<Regarding Method of Access to Local Storage in Shared RewritableRecording Medium (Build-in Memory 110)>

In this case, the playback controller 131 also makes a virtual packagedata access request to the data access controller 135. When the dataaccess controller 135 receives the virtual package data access request,it makes an access-device-type check request to the VPDFS processor 122.In response to that, the data access controller 135 obtains anaccess-device-type check reply result from the VPDFS processor 122.

Here, if the access-device-type check reply result from the VPDFSprocessor 122 indicates an access request for the local storage area111, the data access controller 135 makes a local storage accessibilitycheck request to the LSA usage determination unit 132. In response tothat, the data access controller 135 obtains a local storageaccessibility check reply result from the LSA usage determination unit132. Besides, If the shared-memory-availability information indicates‘valid’, which indicates that the shared rewritable recording medium isin use, the LSA usage determination unit 132 generates a local storageaccessibility check result reply indicating that access is not possible;if the shared-memory-availability information indicates ‘invalid’, theLSA usage determination unit 132 generates a local storage accessibilitycheck reply result indicating that access is possible.

If the local storage accessibility check reply result obtained from theLSA usage determination unit 132 indicates that access is possible, thedata access controller 135 sends local-storage access-start notificationto the LSA usage determination unit 132, and then sends a local storagearea access request to the VPDFS processor 122. The VPDFS processor 122sends the received local storage area access request to the build-inmemory 110.

If the received local storage area access request is a read request, thebuild-in memory 110 reads data from the local storage area 111. Thebuild-in memory 110 sends the read data to the VPDFS processor 122, andthe VPDFS processor 122 causes the memory 125 to store the receiveddata. Upon completion of the reading of the data from the local storagearea 111, the VPDFS processor 122 sends local-storage access-completionnotification to the data access controller 135. When the data accesscontroller 135 receives the local-storage access-completionnotification, it sends local-storage access-end notification to the LSAusage determination unit 132, and then sends virtual-package-dataaccess-completion notification to the playback controller 131.

When the playback controller 131 has received the virtual-package-dataaccess-completion notification, if the issued virtual package dataaccess request is a playback control data read request, the playbackcontroller 131 itself processes the data in the same way as in the caseof BD access. Furthermore, if the issued virtual package data accessrequest is a read request of audio-video stream data, the playbackcontroller 131 transfers the read data from the memory 125 to thedecoder 102 and causes the decoder 102 to decode the audio-video streamdata by making a decode start request to the decoder 102.

On the other hands, if the received local storage area access request isa write request, since a data stored in the memory 125 is sent from theVPDFS processor 122, the build-in memory 110 records the received datain the local storage area 111. Upon completion of the writing of thedata to the local storage area 111, the VPDFS processor 122 sends alocal-storage access-completion notification to the data accesscontroller 135. Having received the local-storage access-completionnotification, the data access controller 135 sends a local-storageaccess notification to the LSA usage determination unit 132, and thensends virtual-package-data access-completion notification to theplayback controller 131.

Here, the LSA usage determination unit 132 sets the shared-memoryavailability information to ‘valid’ during the device access period,from the local-storage access-start notification to the local-storageaccess-end notification. If the LSA usage determination unit 132receives the local-storage access-end notification, it sets theshared-memory-availability information to ‘invalid’.

<Regarding Method of Access to Application Data Area in SharedRewritable Recording Medium (Build-in Memory 110)>

The processing when the program execution unit 133 accesses theapplication data area 112 in the build-in memory 110 will now bedescribed.

In the application data area 112, setup information data that the userhas set on the playback device setup screen of the playback device 100,playback position resume information data created at the time whenplayback is stopped, playback list information for a memory device inwhich music files, moving picture files, or the like are recorded,program update data for the control unit 120 of the playback device 100,and other data are stored as files.

For example, in a case where the user displays the playback device setupscreen, the program execution unit 133 makes an access request to the ADaccess processor 134 in order to read the playback device setup datafile recorded in the application data area 112. Upon receiving theaccess request, the AD access processor 134 makes a file system dataaccess request to the data access controller 135.

Having received the file system data access request, the data accesscontroller 135 makes an access-device-type check request to the FSprocessor 123 to ask whether the access request is an access request forthe application data area 112 or an access request for the memory device170. In response to that, the data access controller 135 obtains anaccess-device-type check reply result from the FS processor 123. Thefile system data access request includes full path information orrelative path information for accessing the desired file. On the basisof the path information, the FS processor 123 refers to the fileallocation table included in the file system data stored in the memory125 and identification information for identifying the recording deviceand thereby determining whether the access request is an access requestfor the application data area 112 or an access request for the memorydevice 170. Then, the FS processor 123 generates an access-device-typecheck reply result according to the result of the determination.

In a case where the access-device-type check reply result from the FSprocessor 123 indicates an access request for the application data area112, the data access controller 135 makes an application dataaccessibility check request to the LSA usage determination unit 132. Ina response to that, the data access controller 135 obtains anapplication-data accessibility-check reply result from the LSA usagedetermination unit 132. If the shared-memory-availability informationstored in the memory 125 indicates ‘valid’, the LSA usage determinationunit 132 generates an application data accessibility check result replyindicating that access is not possible, and if the shared memoryavailability information indicates ‘invalid’, the LSA usagedetermination unit 132 generates an application-data accessibility-checkreply result indicating that access is possible.

If the application-data accessibility-check reply result obtained fromthe LSA usage determination unit 132 indicates that access is possible,the data access controller 135 sends application-data access-startnotification to the LSA usage determination unit 132, and then sends anapplication data area access request to the FS processor 123. The FSprocessor 123 sends the received application data area access request tothe build-in memory 110.

Having received the application data area access request from the FSprocessor 123, the build-in memory 110 reads the data from theapplication data area 112. Then, the build-in memory 110 sends the readdata to the FS processor 123. The FS processor 123 stores the receiveddata in the memory 125. Upon completion of the reading of the data fromthe application data area 112, the FS processor 123 sends applicationdata area access-completion notification to the data access controller135. Having received the application-data-area access-completionnotification, the data access controller 135 sends application-dataaccess-end notification to the LSA usage determination unit 132, andthen sends file-system-data access-completion notification to theplayback controller 131.

When the AD access processor 134 receives the file-system-dataaccess-completion notification, it notifies the program execution unit133 of access completion. The program execution unit 133 reads theplayback device setup data from the memory 125 and constructs video datafor the playback device setup screen as GUI graphic data. Then, theprogram execution unit 133 sends the generated video data to the outputcontroller 103. The output controller 103 superposes the received videodata on the video data decoded by the decoder 102, thereby displayingthe playback device setup screen on the monitor 160.

Next, If, on the basis of the playback device setup screen displayed onthe monitor 160, the user alters the setup content via an input unitsuch as a remote control which is not shown, the program execution unit133 needs to write the playback device setup data back to the playbackdevice setup data file in the application data area 112. Accordingly, inorder to write the altered playback device setup data file in theapplication data area 112, the program execution unit 133 makes anaccess request to the AD access processor 134. Having received theaccess request, the AD access processor 134 makes a file system dataaccess request to the data access controller 135.

If the data access controller 135 receives the file system data accessrequest, it makes an access-device-type check request to the FSprocessor 123 to ask whether the access request is an access request forthe application data area 112 or an access request for the memory device170. Here, if the access-device-type check reply result from the FSprocessor 123 indicates an access request for the application data area112, the data access controller 135 makes an application dataaccessibility check request to the LSA usage determination unit 132. Ifthe application-data accessibility-check reply result obtained from theLSA usage determination unit 132 indicates that access is possible, thedata access controller 135 sends application-data access-startnotification to the LSA usage determination unit 132, and then sends theFS processor 123 an application data area access request. The FSprocessor 123 sends the received application data area access request tothe build-in memory 110.

When the build-in memory 110 receives the application data area accessrequest from the FS processor 123 and also receives the playback devicesetup data stored in the memory 125 from the FS processor 123, itrecords the received playback device setup data as a playback setup datafile in the application data area 112. Upon completion of the writing ofthe data to the application data area 112, the FS processor 123 sendsapplication-data-area access-completion notification to the data accesscontroller 135. Upon receiving the application-data-areaaccess-completion notification, the data access controller 135 sendsapplication-data access-end notification to the LSA usage determinationunit 132, and then sends file-system-data access-completion notificationto the AD access processor 134. Having received the file-system-dataaccess-completion notification, the AD access processor 134 notifies theprogram execution unit 133 of access completion.

Here, the LSA usage determination unit 132 sets the shared-memoryavailability information to ‘valid’ during the device access period,from the local-storage access-start notification to the local-storageaccess-end notification. When the LSA usage determination unit 132receives the local-storage access-end notification, it sets theshared-memory-availability information to ‘invalid’.

<Regarding Method of Access to Rewritable Recording Medium (MemoryDevice 170)>

A method of accessing the memory device 170, which is not a sharedrewritable recoding medium, will also be described. As an example,playback processing of multimedia format AV files such as music files,still-image files, or moving picture files recorded in the memory device170 will be described.

When the user connects the memory device 170 to the interface 105, thedevice detector 124 detects that a device is connected to the interface105. When the device detector 124 detects the connection of a device tothe interface 105, the program execution unit 133 obtains the devicetype of the device connected to the interface 105. In a case where thedevice type is a memory device, in order to construct the playback listscreen for the music files, still-image files, or moving picture filesfrom the directory file structure recorded in the memory device 170, theprogram execution unit 133 makes an access request to the AD accessprocessor 134. Having receives the access request, the AD accessprocessor 134 makes a file system data access request to the data accesscontroller 135.

Upon receiving the file system data access request, the data accesscontroller 135 makes an access-device-type check request to the FSprocessor 123 to ask whether the access is an access request for theapplication data area 112 or an access request for the memory device170. In response to that, the data access controller 135 obtains anaccess-device-type check reply result from the FS processor 123.

If the access-device-type check reply result from the FS processor 123indicates an access request to the memory device 170, the data accesscontroller 135 sends the FS processor 123 a memory device accessrequest. The FS processor 123 sends the received memory device accessrequest to the memory device 170 via the interface 105.

The memory device 170 receives the memory device access request from theFS processor 123 and reads the file system data. Then, the memory device170 sends the read file system data to the FS processor 123. The FSprocessor 123 stores the received file system data in the memory 125.Upon completion of the reading of the file system data, the FS processor123 sends a memory-device access-completion notification to the dataaccess controller 135. Having received the memory-deviceaccess-completion notification, the data access controller 135 sends afile-system-data access-completion notification to the AD accessprocessor 134.

The AD access processor 134 receives the file-system-dataaccess-completion notification and notifies the program execution unit133 of access completion. By reading the file system data stored in thememory 125, the program execution unit 133 constructs the video data fora playback list screen on the basis of the directory files recorded inthe memory device 170. The program execution unit 133 then sends thegenerated video data to the output controller 103. The output controller103 superposes the received video data on the video data decoded by thedecoder 102, thereby displaying the playlist screen on the monitor 160.

Next, in a case where, on the basis of the playback list screendisplayed on the monitor 160, the user selects content to be played backvia an input unit such as a remote control which is not shown, theprogram execution unit 133 notifies the playback controller 131 of theAV file information corresponding to the content selected by the userand makes a content playback request.

When the playback controller 131 accesses to the AV file, it makes afile system access request to the data access controller 135. Havingreceived the file system access request, the data access controller 135makes an access-device-type check request to the FS processor 123 to askwhether the access request is an access request for the application dataarea 112 or an access request for the memory device 170. In response tothat, the data access controller 135 obtains an access-device-type checkreply result from the FS processor 123.

If the access-device-type check reply result from the FS processor 123indicates an access request to the memory device 170, the data accesscontroller 135 sends a memory device access request to the FS processor123. The FS processor 123 sends the received memory device accessrequest to the memory device 170 via the interface 105.

The memory device 170 receives the memory device access request from theFS processor 123, reads the AV file, and sends the read AV file to theFS processor 123. The FS processor 123 stores the received AV file inthe memory 125. It is assumed that the AV file being read here is anaudio-video data stream. Upon completion of the reading of the data, theFS processor 123 sends a memory-device access-completion notification tothe data access controller 135. When the data access controller 135receives the memory-device access-completion notification, it sendsfile-system-data access-completion notification to the AD accessprocessor 134.

Having received the file-system-data access-completion notification, theplayback controller 131 transfers the audio-video data stream stored inthe memory 125 to the decoder 102 and causes the decoder 102 to decodethe audio-video stream data.

To construct a highly functional playback list screen, the programexecution unit 133 may have a search function in which, by reading taginformation recorded in the header files of music files and performingprocessing similar to processing described above on the artistinformation, title information, album information, composer information,and so on included in the tag information, it constructs a database ofplayback list and sorts the playback list on the playback list screen.

It is also possible to shorten the processing time for reconstructingthe database of playback list by storing the database information ofplayback list in the application data area 112 as a playback listdatabase file and, when the user connects and disconnects memory devices170, determining whether or not the connected memory device 170 is thememory device that was being used at the time of storing the playbacklist database file.

So far, the processing when a read-only recording medium is inserted,the access method to the read-only recording medium, the access methodto the local storage area in a shared rewritable recording medium, theaccess method to the application data area in the shared rewritablerecording medium, and the access method to the rewritable recordingmedium have been described. Next, access processing including a casewhere another area in the build-in memory 110 is accessed when theshared-memory-availability information possessed by the LSA usagedetermination unit 132 indicates ‘valid’ will be described with FIG. 3referred to.

FIG. 3 is a flowchart showing a process performed in the data accesscontroller 135. The flow in FIG. 3 is started when the data accesscontroller 135 receives an access request.

In step S10, the data access controller 135 determines whether or notthe received access request is an access request for thevirtual-package-data file system. If the received access request is avirtual package data access request, the data access controller 135determines that the received access request is an access request for thevirtual-package-data file system (S10: Yes) and the process proceeds tostep S11. On the other hands, If the received access request is a filesystem data access request, the data access controller 135 determinesthat the received access request is not an access request for thevirtual-package-data file system (S10: No) and the process proceeds tostep S16.

In step S11, the data access controller 135 determines whether or notthe received access request is an access request to the local storagearea 111. If the access-device-type check reply result obtained inresponse to the inquiry to the VPDFS processor 122 indicates an accessrequest for the BD drive 101, the data access controller 135 determinesthat the received access request is not an access request for the localstorage area 111 (S11: No) and the process proceeds to step S12. On theother hands, If the access-device-type check reply result indicates anaccess request for the local storage area 111, the data accesscontroller 135 determines that the received access request is an accessrequest for the local storage area 111 (S11: Yes) and the processproceeds to step S13.

In step S12, the data access controller 135 requests access to the BDdrive 101.

In step S13, the data access controller 135 determines whether or notthe application data area 112 is currently being accessed. If the localstorage accessibility check reply result obtained in response to theinquiry to the LSA usage determination unit 132 indicates that access ispossible, the data access controller 135 determines that the applicationdata area 112 is not being accessed (S13: No) and the process proceedsto step S14. On the other hands, if the local storage accessibilitycheck reply result indicates that access is not possible, the dataaccess controller 135 determines that the application data area 112 iscurrently being accessed (S13: Yes) and the process proceeds to stepS15.

In step S14, the data access controller 135 requests access to the localstorage area 111.

In step S15, the data access controller 135 suspends the access to theapplication data area 112. The process then proceeds to step S14, inwhich the data access controller 135 requests access to the localstorage area 111. When suspending access to the application data area112 in step S15, the data access controller 135 sends anapplication-data-area access-cancellation notification to the AD accessprocessor 134 to inform it that the access is suspended until alocal-storage access-completion notification is received from the VPDFSprocessor 122. After receiving the local-storage access-completionnotification from the VPDFS processor 122, the data access controller135 sends an application-data access-possible notification to the ADaccess processor 134, informing it that application data access requestsmay be possible again. When the AD access processor 134 receives theapplication-data-area access-cancellation notification, it informs theprogram execution unit 133 that the access has been cancelled. Further,when the AD access processor 134 receives the application-dataaccess-possible notification, it informs the program execution unit 133that access is possible. After receiving an access-cancellationnotification, the program execution unit 133 delays making an accessrequest for the application data area 112 to the AD access processor 134until an access-possible notification is received. In other words, ifthe program execution unit 133 receives an access-cancellationnotification, it sends the cancelled access request (the access requestfor which a cancellation notification was received before accesscompletion is received) to the AD access processor 134 again after theaccess-possible notification is sent.

In step S16, the data access controller 135 determines whether or notthe received access request is an access request for the applicationdata area 112. If the access-device-type check reply result in responseto the inquiry to the FS processor 123 indicates an access request forthe application data area 112, the data access controller 135 determinesthat the received access request is an access request for theapplication data area 112 (S16: Yes) and the process proceeds to stepS17. If the access-device-type check reply result indicates an accessrequest for the memory device 170, the data access controller 135determines that the received access request is not an access request forthe application data area 112 (S16: No) and the process proceeds to stepS20.

In step S17, the data access controller 135 determines whether or notthe local storage area 111 is currently being accessed. If theapplication data accessibility check replay result in response to theinquiry to the LSA usage determination unit 132 indicates that access isnot possible, the data access controller 135 decides that the localstorage area 111 is currently being accessed (S17: Yes) and the processproceeds to step S18. If the application-data accessibility-check replyresult indicates that access is possible, the data access controller 135decides that the local storage area 111 is not currently being accessed(S17: No) and the process proceeds to step S19.

In step S18, in order to deny access to the application data area, thedata access controller 135 sends an application-data-areaaccess-cancellation notification to the AD access processor 134. Havingreceived the application-data-area access-cancellation notification, theAD access processor 134 notifies the program execution unit 133 ofaccess cancellation. In the same way as step S15, the program executionunit 133 delays making an access request for the application data area112 to the AD access processor 134 until an access-possible notificationis received.

In step S19, the data access controller 135 makes an access request forthe application data area 112.

In step S20, the data access controller 135 makes an access request forthe memory device 170.

As mentioned above, according to the playback device 100 in the firstembodiment, it is possible to prevent reducing the transfer speedrequired in the local storage, even when the same device is used as botha local storage area device and an application data area device. Whenaccess to the local storage area 111 is requested during access to theapplication data area 112, the access to the application data area 112is suspended so that the local storage area 111 can be accessedpreferentially. When access to the application data area 112 isrequested during access to the local storage area 111, the access to theapplication data area 112 can be restrained.

In the first embodiment described above, in response to an accessrequest from the playback controller 131 or AD access processor 134, thedata access controller 135 determines any one to be access from among aread-only recording medium, a local storage area in a shared rewritablerecording medium, an application data area in the shared rewritablerecording medium, or a rewritable recording medium, and makes an accessrequest to the VPDFS processor 122 or FS processor 123 according to theaccess status of the shared rewritable recording medium. This scheme isnot limiting, however. For example, while (a virtual file system of)virtual package data are (is) present, the LSA usage determination unit132 may set the shared-memory availability information to ‘valid’, whichindicates that the memory having the local storage area 111 is busy.This enables the data access controller 135 to determine whether or notvirtual package data have been constructed from the BD drive 101 andlocal storage area 111 and then request access to the application dataarea 112 can be done with only steps S16-S20 in FIG. 3. This canprevent, in the same way as above configuration, the required localstorage transfer speed for a local storage from being reduced.

In addition, the data access controller 135 may also monitor the maximumtransfer speed of the build-in memory 110 including the local storagearea 111 and application data area 112, and may perform access even whenaccess to the local storage area 111 is carrying out, in a case wherethe file size of an access file corresponding to an access request fromthe AD access processor 134 is smaller than a predetermined value andtransfer speed required for a local storage can be obtained even ifconcurrent access is performed. Therefore, transfer speed required forlocal storage is maintained even if the local storage area 111 andapplication data area 112 are accessed concurrently.

In the first embodiment described above, the local storage area 111 andthe application data area 112 are formed in the build-in memory 110, butthe configuration is not limited to this. For example, it is possiblethat a build-in memory 110 is not included in the playback device 100and processing similar to the above is carried out with a the localstorage area 111 and application data area 112 which are formed in thememory device 170.

In the first embodiment described above, the LSA usage determinationunit 132 sets the shared-memory-availability information to ‘valid’during device access periods, that is, during the period from alocal-storage access-start notification to the local-storage access-endnotification and during the period from an application-data access-startnotification to the application-data access-end notification, but theconfiguration is not limited to this. For example, as the shared-memoryavailability information, local-storage-access availability informationindicating whether or not the local storage is currently being accessed,and application-data-access availability information indicating whetheror not the application data are being accessed may be stored in thememory 125. In addition, each of the local-storage-access availabilityinformation and application-data-access availability information mayinclude information indicating whether the availability information fora write request or a read request.

Second Embodiment

A second embodiment will now be described below with reference to thedrawings.

FIG. 4 is a block diagram showing a configuration of a playback device200 in the second embodiment. The playback device 200 is connected to aplurality of monitors 260A, 260B and speakers 261A, 261B in a rearentertainment system or the like, and is configured to enable viewingand listening of either the same content or viewing and listeningdifferent content.

As shown in FIG. 4, the playback device 200 includes a BD drive 101, afirst decoder 202A, a second decoder 202B, a first output controller203A, a second output controller 203B, a network device 104, a firstinterface (hereinafter referred to as a first I/F) 205A, a secondinterface (hereinafter referred to as a second I/F) 205B, a build-inmemory 110, and a control unit 220. The playback device 200 in thesecond embodiment differs from the playback device 100 in the firstembodiment in that it includes a plurality of decoders 202A, 202B, aplurality of output controllers 203A, 203B, and a plurality of I/F's205A, 205B, and in the configuration of the control unit 220.

The playback device 200 in the second embodiment is connected to aplurality of monitors 260A, 260B and speakers 261A, 261B. For example,the first monitor 260A and the first speaker 261A are disposed in theleft side of rear seat of a vehicle so that a user in the left side ofrear seat of the vehicle views and listens. The second monitor 260A andsecond speaker 261B are disposed in the right side of rear seat of thevehicle so that a user in the right rear seat of the vehicle views andlistens. Further, the playback device 200 includes the first outputcontroller 203A for outputting video signals and audio signals to thefirst monitor 260A and first speaker 261A and the second outputcontroller 203B for outputting video signals and audio signals to thesecond monitor 260B and second speaker 261B. The monitors 260A, 260B,speakers 261A, 261B, and output controllers 203A, 203B have the samefunctions as the monitor 160, speaker 161, and output controller 103,respectively, in the first embodiment.

The first output controller 203A is connected to the first decoder 202A,which has the same functions as the decoder 102 in the first embodiment,and the second output controller 203B is connected to the second decoder202B, which has the same functions as the decoder 102 in the firstembodiment. In a case where a user simultaneously views and listens thesame content, the output signal from either the first decoder 202A orsecond decoder 202B is output to both output controllers 203A, 203B, andin a case where a user asynchronously views and listens differentcontents, the output signals from the decoders 202A, 202B are output tothe respective output controllers 203A, 203B.

The control unit 220 controls each unit of the playback device 200.

The control unit 220 includes an optical disk detector 121, a VPDFSprocessor 122, an FS processor 123, a device detector 124, a memory 125,and a processing section 230. The control unit 220 in the secondembodiment differs from the control unit 120 in the first embodiment inregard to the configuration of the processing section 230.

The processing section 230 executes the processing performed in theplayback device 200.

FIG. 5 is a block diagram schematically showing a configuration of theprocessing section 230. As shown in the figure, the processing section230 includes a first playback controller 231A, a second playbackcontroller 231B, an LSA usage determination unit 132, a first programexecution unit 233A, a second program execution unit 233B, a first ADaccess processor 234A, a second AD access processor 234B, and a dataaccess controller 235.

In the second embodiment, in which different contents can be playedback, a plurality of playback controllers 231A, 231B, program executionunits 233A, 233B, and AD access processor 234A, 234B each are provided.The playback controller 231A, first program execution unit 233A, andfirst AD access processor 234A have the same functions as the playbackcontroller 131, program execution unit 133, and AD access processor 134,respectively, in the first embodiment. The second playback controller231B, second program execution unit 233B, and second AD access processor234B has the same functions as the playback controller 131, programexecution unit 133, and AD access processor 134, respectively, in thefirst embodiment.

Although the BD drive 101 is randomly accessible recording media,because of the seek processing characteristic of an optical disk device,there is a problem in practicability from the standpoint of theprocessing performance of the optical drive to playing back of differentscenes by the first playback controller 231A and second playbackcontroller 231B. Therefore, the first playback controller 231A andsecond playback controller 231B cannot carry out processing to accessthe BD drive 101 at the same time, and only one of them can carry outsuch processing. In other words, in a case where the BD drive 101 isused, the playback device 200 in the second embodiment can perform onlysynchronized viewing and listening of the same content.

The data access controller 235 performs the same processing as the dataaccess controller 135 in the first embodiment in response to accessrequests from the first playback controller 231A, first AD accessprocessor 234A, second playback controller 231B, and secondapplication-data access processor 234B.

In a case where a BD-ROM 150 is inserted into the BD drive 101, theVPDFS processor 122 constructs virtual-package-data-file-system data sothat data recorded in the BD-ROM 150 and data recorded in the localstorage area 111 of the build-in memory 110 are combined to be treatedas virtual package data. Then, one of the first playback controller 231Aand second playback controller 231B, which have the same BDMV playbackfunction as the playback controller 131 in the first embodiment,performs BDMV playback and at least one of the first output controller203A and second output controller 203B performs output, therebyenabling, for example, at least one of the users in the left side ofrear seat and the right side of rear seat to view and listen thecontent.

In addition, the plurality of I/F's 205A, 205B are included in theplayback device 200 in the second embodiment so that a plurality ofmemory devices 270A, 270B can be connected. The first memory device 270Aand second memory device 270B each are memory devices in whichmultimedia format data are recorded as AV files like the memory device170 in the first embodiment, and can be implemented by SD cards, HDDs,or the like. For example, the first memory device 270A is connected tothe first I/F 205A; the second memory device 270B is connected to thesecond I/F 205B.

In playback of memory devices 270A, 270B in which AV files are recorded,in response to an access request from at least one of the first playbackcontroller 231A and second playback controller 231B, an AV file isplayed back in the same way as by the playback controller 131 in thefirst embodiment, and output is performed from at least one of the firstoutput controller 203A and second output controller 203B so that, forexample, at least one of the users in the left side of rear seat and theright side of rear seat can view and listen to the output.

In the second embodiment, even if the plurality of playback controllers231A, 231B, program execution units 233A, 233B, and AD access processors234A, 234B make access requests to the build-in memory (single memory)110, in which a local storage area 111 and an application data area 112are formed, access to the application data area 112 can be restrained asin the first embodiment.

In a case where an access request for the local storage area 111 fromthe first playback controller 231A or second playback controller 231Band an access request for the application data area 112 from the firstAD access processor 234A or second AD access processor 234B occursimultaneously, in order to secure the transfer speed required for localstorage, the data access controller 235 may monitor the maximum transferspeed of the build-in memory 110 and set priority levels to accessrequests from the first AD access processor 234A and second AD accessprocessor 234B according to the required file size to be accessed. Forexample, the priority level may increase with decreasing the file sizeof the file to be accessed. The data access controller 235 may also makefile system data access requests to the FS processor 123 according tothe priority levels of the access requests. For example, access requestsmay be made in their order of priority, or by selecting access requestswith higher priority than a predetermined priority.

DESCRIPTION OF REFERENCE CHARACTERS

100, 200 playback device, 101 BD drive, 102 decoder, 202A first decoder,202B second decoder, 103 output controller, 203A first outputcontroller, 203B second output controller, 104 network device, 105interface, 205A first interface, 205B second interface, 110 build-inmemory, 120, 220 control unit, 121 optical disk detector, 122virtual-package-data file system processor, 123 file system processor,124 device detector, 125 memory, 130, 230 processing unit, 131 playbackcontroller, 231A first playback controller, 231B second playbackcontroller, 132 local-storage-area usage determination unit, 133 programexecution unit, 233A first program execution unit, 233B second programexecution unit, 134 application-data access processor, 234A firstapplication-data access processor, 234B second application-data accessprocessor, 135, 235 data access controller.

What is claimed is:
 1. A playback device comprising: avirtual-package-data file system processor to treat a combination offirst data recorded in a first recording unit and second data recordedin a local storage area in a second recording unit including the localstorage area and an application data area as virtual package data andperforms reading and writing of the virtual package data; a file systemprocessor to perform reading and writing of application data recorded inthe application data area; a playback controller to control playback ofthe virtual package data; a processing execution unit to process theapplication data; and a data access controller to cause thevirtual-package-data file system processor to perform reading or writingof the virtual package data according to a first access request from theplayback controller, the first access request requesting reading andwriting of the virtual package data, and to cause the file systemprocessor to perform reading or writing of the application dataaccording to a second access request from the processing execution unit,the second access request requesting reading or writing of theapplication data; wherein in a case where the first access request fromthe playback controller is a request for requesting reading or writingin the local storage area, the data access controller causes thevirtual-package-data file system processor to perform the reading orwriting of the virtual package data with priority over the reading orwriting of the application data by the file system processor.
 2. Theplayback device of claim 1, wherein, in a case where the data accesscontroller receives the first access request that requests reading orwriting in the local storage area from the playback controller while thedata access controller is causing the file system processor to performthe reading or writing of the application data according to the secondaccess request from the processing execution unit, the data accesscontroller cancels the reading or writing of the application data andcauses the virtual-package-data file system processor to perform thereading or writing of the virtual package data according to the receivedfirst access request.
 3. The playback device of claim 1, wherein, in acase where the data access controller is causing thevirtual-package-data file system processor to perform the reading orwriting of the virtual package data in the local storage area accordingto the first access request from the playback controller when the dataaccess controller receives the second access request from the processingexecution unit, the data access controller denies the received secondaccess request.
 4. The playback device of claim 1, wherein, in a casewhere the data access controller is causing the virtual-package-datafile system processor to perform the reading or writing of the virtualpackage data in the local storage area according to the first accessrequest from the playback controller when the data access controllerreceives the second access request from the processing execution unit,the data access controller causes the file system processor to performthe reading or writing of the application data if the application datato be read or written according to the received second access requesthave a size smaller than a predetermined size, and denies the receivedsecond access request if the application data to be read or writtenaccording to the received second access request have a size equal to orgreater than the predetermined size.
 5. The playback device of claim 1,wherein, in a case where the data access controller is causing thevirtual-package-data file system processor to perform the reading orwriting of the virtual package data in the local storage area accordingto the first access request from the playback controller when the dataaccess controller receives the second access request from the processingexecution unit, the data access controller causes the file systemprocessor to perform the reading or writing of the application data onthe basis of a priority level of the application data to be read orwritten according to the received second access request.
 6. The playbackdevice of claim 5, wherein the priority level increases in value withdecreasing size of the application data.
 7. The playback device of claim1, wherein the first recording unit is configured by a drive unit intowhich a playback-only recording medium on which the first data arerecorded is inserted, the drive unit being capable of reading the firstdata from the playback-only recording medium.
 8. The playback device ofclaim 1, wherein the playback controller identifies the virtual packagedata to be played back; the playback device further comprising aplayback unit to play back the virtual package data identified by theplayback controller.
 9. The playback device of claim 8, wherein theplayback device is equipped with a plurality of the playbackcontrollers, the playback units, and the processing execution units. 10.A playback method comprising: controlling playback of the virtualpackage data; performing reading or writing of the virtual package dataobtained by combining first data recorded in a first recording unit andsecond data recorded in a local storage area in a second recording unitaccording to a first access request; processing application datarecorded in an application data area in the second recording unit;performing reading or writing of the application data recorded in theapplication data area in the second recording unit according to a secondaccess request; and in a case where the first access request is arequest for requesting reading or writing in the local storage area,causing to perform the reading or writing of the virtual package datawith priority over the reading or writing of the application data. 11.The playback method of claim 10, further comprising, in a case where thefirst access request that requests reading or writing in the localstorage area is issued while the reading or writing of the applicationdata are being performed canceling the reading or writing of theapplication data and reading or writing the virtual package dataaccording to the issued first access request.
 12. The playback method ofclaim 10, further comprising, in a case where the reading or writing ofthe virtual package data in the local storage area is being performedwhen the second access request is issued denying the issued secondaccess request.
 13. The playback method of claim 10, in a case where thereading or writing of the virtual package data in the local storage areais being performed when the second access request is issued performingthe reading or writing of the application data to be read or written ifthe application data to be read or written according to the issuedsecond access request have a size smaller than a predetermined size, anddenying the received second access request if the application data to beread or written according to the issued second access request have asize equal to or greater than the predetermined size.
 14. The playbackmethod of claim 10, wherein, in a case where the reading or writing ofthe virtual package data in the local storage area is being performedwhen the second access request is issued performing the reading orwriting of the application data to be read or written on the basis of apriority level of the application data to be read or written accordingto the issued second access request.
 15. The playback method of claim14, wherein the priority level increases in value with decreasing sizeof the application data.
 16. The playback method of claim 10, whereinthe first recording unit is configured by a drive unit into which aplayback-only recording medium on which the first data are recorded isinserted, the drive unit being capable of reading the first data fromthe playback-only recording medium.